1873.] J. Wood-Mason — On Eliopalorhync'hus Kroyeri. 173 



out just in front of the first pair of legs, divides the oculigerous from the first 

 thoracic somite. 



The cephalic appendages of the first pair are absent. Those of the 

 second pair are about If times as long as the rostrum with which they 

 lie in the same horizontal line, being articulated one on each side of it 

 to the anterior end of the oculigerous somite, are filiform, excessively 

 slender, and composed of nine joints. The first joint is subglobular, being 

 nearly as broad as long, much broader than any of the succeeding joints ; 

 the second greatly elongated and slightly expanded at the apex ; the third 

 is very short and slightly curved ; the fourth is greatly elongated, but not 

 so much so as the second ; the fifth is shorter than either of the four equal 

 terminal joints which, together with the fifth and the distal half of the fourth, 

 are fringed with short and very delicate cilia. Those of the third pair 

 are also extremely slender, are articulated, a little posteriorly and internally 

 to the second pair, to minute processes springing from the ventral arc of the 

 oculigerous somite and meeting in the middle line. They are composed of 

 ten joints, of which the first is minute, the two next equal and cylindrical, 

 the third greatly elongated and just perceptibly expanded at the apical end ; 

 the fourth short, scarcely longer than the second of the two basal joints, and 

 curved ; the fifth is likewise greatly elongated, but more expanded at the apex 

 and longer than the third ; the four terminal joints are short, slightly de- 

 crease in length from the first to the last which comes suddenly to a subacute 

 incurved point forming a sort of claw, are curved, fringed on their inner and 

 concave margins with cilia and minute spinules, and capable of being coiled 

 tightly together so as to form a prehensile organ. 



Both pairs of appendages are elbowed at a short joint, intercalated 

 between two long ones, viz., the second pair between the 2nd and 4th, 

 the third between the 3rd and 5th joints. 



In many other species the terminal joints of the tliird pair of cephalic 

 appendages {'pedes accessorii) will probably be found to be similarly modified 

 as a prehensile organ ; an examination of 0. F. Miiller's faithful figures of 

 JSfympho7i grossipes, Fabr. in the Zoologica Danica^ would, in fact, alone 

 suffice to show the existence of such a modification in that species, even if 

 Kroyerf had not described it in his diagnoses of the genera Nymphon and 

 Zetes, without, however, offering any interpretation of the structure. 



The oculigerous somite has its anterior margin straight, and is but 

 faintly constricted in front of the eye-tubercle. 



TlhQ first thoracic somite, if its distinctness from the oculigerous somite 

 be admitted, is very short. Of the remaining somites, the second and third are 

 subequal, the former being if anything the longer ; are as perfectly cylindrical, 

 * Op. cit,, pi. cxix, figs. 5 et 8. 

 t Naturlust. Tidssk., 1844, pp. 108 et 116. 

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